GeForce GTX 660 MSI OC 2GB Edition is a special edition of GeForce GTX 660. The new features include the Propeller Blade Technology solution which generates 20% more airflow than traditional fan design, according to MSI. In terms of overclocking, the base-clock was increased from 980MHz to 1006MHz and the boost clock can now reach 1072MHz, instead of 1033MHz. The memory clock was left untouched. The overclocking is therefore somewhat significant and the performance boost is around 5% when compared to the standard GeForce GTX 660.